Re: [PATCH 2/2] virtio_scsi: Implement fc_host
On Tue, Jan 17, 2017 at 10:05:00PM +0800, Fam Zheng wrote: > On Tue, 01/17 14:17, Paolo Bonzini wrote: > > > > > > On 16/01/2017 18:26, Fam Zheng wrote: > > >> Is the endianness correct for big-endian host here? > > > > > > I think so. The fc_host sysfs uses u64 to represent port_name and > > > node_name, > > > this patch does the same, so using virtio_* helpers for these fields > > > should > > > handle the endianness correctly. > > > > I was suspicious about it because they are defined as "u8 x[8]" in the > > virtio_scsi_config struct. So you would need to read with > > virtio_cread_bytes and pass the result to wwn_to_u64. > > > > For example, if you have 0x500123456789abcd this would be > > > > 0x50 0x01 0x23 0x45 0x67 0x89 0xab 0cd > > > > in virtio_scsi_config, and then virtio_cread64 would read it as a > > little-endian u64, 0xcdab896745230150. Maybe your QEMU patch is also > > writing things as little-endian 64-bit integers, rather than 8-element > > arrays of bytes? > > Yes, they all used 64-bit integers in a "less surprising" endian. I think > there > is an endianness conecpt to WWN, as in 0x500123456789abcd; and there is an > native endianness to virtio, which is little-endian. If we use a "u8 x[8]" > type > in the spec and want the WWN's MSB, namely the 0x50 stuff, to be the first > byte, > is it worth to explicitly document that to avoid confusion? > > Fam Can't hurt, for sure. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] virtio_scsi: Implement fc_host
On Tue, 01/17 14:17, Paolo Bonzini wrote: > > > On 16/01/2017 18:26, Fam Zheng wrote: > >> Is the endianness correct for big-endian host here? > > > > I think so. The fc_host sysfs uses u64 to represent port_name and node_name, > > this patch does the same, so using virtio_* helpers for these fields should > > handle the endianness correctly. > > I was suspicious about it because they are defined as "u8 x[8]" in the > virtio_scsi_config struct. So you would need to read with > virtio_cread_bytes and pass the result to wwn_to_u64. > > For example, if you have 0x500123456789abcd this would be > > 0x50 0x01 0x23 0x45 0x67 0x89 0xab 0cd > > in virtio_scsi_config, and then virtio_cread64 would read it as a > little-endian u64, 0xcdab896745230150. Maybe your QEMU patch is also > writing things as little-endian 64-bit integers, rather than 8-element > arrays of bytes? Yes, they all used 64-bit integers in a "less surprising" endian. I think there is an endianness conecpt to WWN, as in 0x500123456789abcd; and there is an native endianness to virtio, which is little-endian. If we use a "u8 x[8]" type in the spec and want the WWN's MSB, namely the 0x50 stuff, to be the first byte, is it worth to explicitly document that to avoid confusion? Fam -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] virtio_scsi: Implement fc_host
On 16/01/2017 18:26, Fam Zheng wrote: >> Is the endianness correct for big-endian host here? > > I think so. The fc_host sysfs uses u64 to represent port_name and node_name, > this patch does the same, so using virtio_* helpers for these fields should > handle the endianness correctly. I was suspicious about it because they are defined as "u8 x[8]" in the virtio_scsi_config struct. So you would need to read with virtio_cread_bytes and pass the result to wwn_to_u64. For example, if you have 0x500123456789abcd this would be 0x50 0x01 0x23 0x45 0x67 0x89 0xab 0cd in virtio_scsi_config, and then virtio_cread64 would read it as a little-endian u64, 0xcdab896745230150. Maybe your QEMU patch is also writing things as little-endian 64-bit integers, rather than 8-element arrays of bytes? Paolo > Maybe we should use u64 in struct virtio_scsi_config as well? -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] virtio_scsi: Implement fc_host
On Tue, 01/17 03:02, kbuild test robot wrote: > Hi Fam, > > [auto build test ERROR on linus/master] > [also build test ERROR on v4.10-rc4 next-20170116] > [if your patch is applied to the wrong git tree, please drop us a note to > help improve the system] > > url: > https://github.com/0day-ci/linux/commits/Fam-Zheng/virtio-scsi-Implement-FC_HOST-feature/20170117-011950 > config: i386-randconfig-r0-201703 (attached as .config) > compiler: gcc-5 (Debian 5.4.1-2) 5.4.1 20160904 > reproduce: > # save the attached .config to linux build tree > make ARCH=i386 > > All errors (new ones prefixed by >>): > >drivers/built-in.o: In function `init': > >> virtio_scsi.c:(.init.text+0x10d52): undefined reference to > >> `fc_attach_transport' >drivers/built-in.o: In function `fini': > >> virtio_scsi.c:(.exit.text+0x14a4): undefined reference to > >> `fc_release_transport' This is good catch. Looks like virtio-scsi will now have to depend on fc, or we wrap the fc code with #ifdef's. Fam -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] virtio_scsi: Implement fc_host
Hi Fam,
[auto build test ERROR on linus/master]
[also build test ERROR on v4.10-rc4 next-20170116]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Fam-Zheng/virtio-scsi-Implement-FC_HOST-feature/20170117-011950
config: arm-vexpress_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget
https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
-O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All errors (new ones prefixed by >>):
drivers/built-in.o: In function `init':
>> drivers/scsi/virtio_scsi.c:1178: undefined reference to `fc_attach_transport'
drivers/built-in.o: In function `fini':
>> drivers/scsi/virtio_scsi.c:1231: undefined reference to
>> `fc_release_transport'
vim +1178 drivers/scsi/virtio_scsi.c
1172 };
1173
1174 static int __init init(void)
1175 {
1176 int ret = -ENOMEM;
1177
> 1178 virtscsi_fc_transport_template =
> fc_attach_transport(_fc_template);
1179 if (!virtscsi_fc_transport_template) {
1180 pr_err("fc_attach_transport() failed\n");
1181 goto error;
1182 }
1183
1184 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1185 if (!virtscsi_cmd_cache) {
1186 pr_err("kmem_cache_create() for virtscsi_cmd_cache
failed\n");
1187 goto error;
1188 }
1189
1190
1191 virtscsi_cmd_pool =
1192 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1193 virtscsi_cmd_cache);
1194 if (!virtscsi_cmd_pool) {
1195 pr_err("mempool_create() for virtscsi_cmd_pool
failed\n");
1196 goto error;
1197 }
1198 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
1199"scsi/virtio:online",
1200virtscsi_cpu_online, NULL);
1201 if (ret < 0)
1202 goto error;
1203 virtioscsi_online = ret;
1204 ret = cpuhp_setup_state_multi(CPUHP_VIRT_SCSI_DEAD,
"scsi/virtio:dead",
1205NULL, virtscsi_cpu_online);
1206 if (ret)
1207 goto error;
1208 ret = register_virtio_driver(_scsi_driver);
1209 if (ret < 0)
1210 goto error;
1211
1212 return 0;
1213
1214 error:
1215 if (virtscsi_cmd_pool) {
1216 mempool_destroy(virtscsi_cmd_pool);
1217 virtscsi_cmd_pool = NULL;
1218 }
1219 if (virtscsi_cmd_cache) {
1220 kmem_cache_destroy(virtscsi_cmd_cache);
1221 virtscsi_cmd_cache = NULL;
1222 }
1223 if (virtioscsi_online)
1224 cpuhp_remove_multi_state(virtioscsi_online);
1225 cpuhp_remove_multi_state(CPUHP_VIRT_SCSI_DEAD);
1226 return ret;
1227 }
1228
1229 static void __exit fini(void)
1230 {
> 1231 fc_release_transport(virtscsi_fc_transport_template);
1232 unregister_virtio_driver(_scsi_driver);
1233 cpuhp_remove_multi_state(virtioscsi_online);
1234 cpuhp_remove_multi_state(CPUHP_VIRT_SCSI_DEAD);
---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
Description: application/gzip
Re: [PATCH 2/2] virtio_scsi: Implement fc_host
Hi Fam, [auto build test ERROR on linus/master] [also build test ERROR on v4.10-rc4 next-20170116] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Fam-Zheng/virtio-scsi-Implement-FC_HOST-feature/20170117-011950 config: i386-randconfig-r0-201703 (attached as .config) compiler: gcc-5 (Debian 5.4.1-2) 5.4.1 20160904 reproduce: # save the attached .config to linux build tree make ARCH=i386 All errors (new ones prefixed by >>): drivers/built-in.o: In function `init': >> virtio_scsi.c:(.init.text+0x10d52): undefined reference to >> `fc_attach_transport' drivers/built-in.o: In function `fini': >> virtio_scsi.c:(.exit.text+0x14a4): undefined reference to >> `fc_release_transport' --- 0-DAY kernel test infrastructureOpen Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation .config.gz Description: application/gzip
Re: [PATCH 2/2] virtio_scsi: Implement fc_host
On Mon, 01/16 17:45, Paolo Bonzini wrote:
>
>
> On 16/01/2017 17:04, Fam Zheng wrote:
> > + node_name = virtio_cread64(vdev,
> > + offsetof(struct virtio_scsi_config, primary_wwnn));
> > + port_name = virtio_cread64(vdev,
> > + offsetof(struct virtio_scsi_config, primary_wwpn));
> > + } else {
> > + node_name = virtio_cread64(vdev,
> > + offsetof(struct virtio_scsi_config, secondary_wwnn));
> > + port_name = virtio_cread64(vdev,
> > + offsetof(struct virtio_scsi_config, secondary_wwpn));
>
> Is the endianness correct for big-endian host here?
I think so. The fc_host sysfs uses u64 to represent port_name and node_name,
this patch does the same, so using virtio_* helpers for these fields should
handle the endianness correctly.
Maybe we should use u64 in struct virtio_scsi_config as well?
Fam
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Re: [PATCH 2/2] virtio_scsi: Implement fc_host
On 16/01/2017 17:04, Fam Zheng wrote:
> + node_name = virtio_cread64(vdev,
> + offsetof(struct virtio_scsi_config, primary_wwnn));
> + port_name = virtio_cread64(vdev,
> + offsetof(struct virtio_scsi_config, primary_wwpn));
> + } else {
> + node_name = virtio_cread64(vdev,
> + offsetof(struct virtio_scsi_config, secondary_wwnn));
> + port_name = virtio_cread64(vdev,
> + offsetof(struct virtio_scsi_config, secondary_wwpn));
Is the endianness correct for big-endian host here?
Thanks,
Paolo
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